1. Field of the Invention
This invention relates generally to turbochargers, and more particularly to means to aid in rapid acceleration of the turbocharger from a low speed to obtain a responsive solid feel in a passenger car and to reduce the lag many times associated with turbocharged internal combustion engines.
2. Description of the Prior Art
Efforts have been made to improve acceleration of turbochargers. One example is a variable-geometry turbocharger described in a paper by Satoh et al. for presentation at the 1983 Tokyo International Gas Turbine Congress held in Tokyo, Japan on Oct. 23-29, 1983. The system controls nozzle vane opening and angle in three positions according to engine speed and accelerator pedal signals. A somewhat similar approach is described in an article entitled Variable-Geometry Turbocharging in Road & Track Magazine and referring to an Arodyne Dallas, Inc. variable vane turbocharger. Another article on that turbocharger appeared in Hot Rod Magazine, Jan. 28, 1983.
The variable-geometry turbocharging has provided a degree of improved performance, where efforts to reduce rotational inertia seem to have limited further potential. The above-mentioned approaches to geometry typically involve many moving parts in a very harsh and corrosive environment. They may have a great future in large machines where adding thirty to sixty parts is possible and may be worth the complication and expense. When the turbocharger is reduced in size so as to be useful on automobile engines, it becomes impractical to miniaturize all these parts. The present invention is directed to reduction of complexity involved in these variable-geometry prior art techniques.